Catherine, the Doujinshi Witch, or the Deadline Witch. She has an urgent nature, always trying to get her latest project out as quickly as possible. Those who blunder into her barrier will find themselves on a rapidly moving treadmill of paper being sucked into her body, which resembles a large printing press. Thus they will have to run as fast as they can just to stay in place (and avoid "playing a role" in her latest production). Indeed, the walls of her barrier consist of a scrapbook of her human victims "preserved" within the pages of her doujins.
This Witch always fears running out of plot ideas; hence her Familiar Bert's duty is to give her ideas. This he does by using his body (which resembles a computer cursor) to pierce into the heads of trapped humans and extract their thoughts.
Her other Familiar Ernest resembles a cupid with a pen in place of his head. His duty is to "ship" any two peoplehe comes across, especially if they're of the same gender. If any of them refuse to fall in love, he squirts them with his ink, sending them falling back into Catherine's maw.
This is obviously Hiyori. I named her after Cathy Guisewhite (I hate that strip, but there aren't a whole lot of female household-name newspaper comic artists in the West, which is a shame. Maybe that's why "four-girl ensemble" manga are so popular).
Take a wild guess as for whom Bert and Ernest are named. ;) People have probably shipping their namesakes since the first generation of Sesame Street watchers became raunchy adolescents who crack up every time they hear the word "gay".